Life’s end Benefits of CannaBidiol and TetrahYdrocannabinol (LiBBY) Open-Label Extension (OLE) Study - PROJECT SUMMARY/ABSTRACT This project will be conducted in the context of the Alzheimer’s Clinical Trials Consortium (ACTC), which is a consulting group of over 100 sites (with 30 leading clinical sites in the Steering Committee) dedicated to Alzheimer’s disease (AD) research and the infrastructures supported by the National Institute on Aging (NIA). The Life’s end Benefits of CannaBidiol and TetrahYdrocannabinol (LiBBY) Study is the first phase 2, multicenter, randomized, double-blind, parallel-group, placebo-controlled,12-week study to evaluate the efficacy and tolerability of an oral combination of two cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), in hospice care eligible patients with agitation and Alzheimer’s disease (AD) or other types of dementia (HAD). We here propose to continue the LiBBY Study beyond the initial 12 weeks with an open label extension (OLE) study design. Although the double-blind, placebo-controlled study will offer important information about the efficacy of the THC/CBD combination in this population, other relevant clinical questions still need to be answered. Specifically, 1. do participants treated with THC and CBD maintain their level of response with prolonged exposure and do participants treated with placebo respond to the THC/CBD oral combination during the OLE study?, 2. does treatment with THC and CBD have an impact on lifespan and site of care with prolonged exposure?, 3. does treatment with THC and CBD impact quality of life with prolonged exposure?, and 4. does treatment with THC and CBD have an impact on caregiver burden with prolonged exposure? Furthermore, despite the fact that our approach may be controversial, the investigators feel strongly that for humanitarian reasons, active treatment should be offered to all individuals in the study including those receiving placebo in the double-blind, placebo-controlled study. To that end, since the double-blind, placebo- controlled study is ongoing, the Alzheimer’s Therapeutic Research Institute (ATRI) has agreed to provide bridge funding to allow individuals currently in the double-blind, placebo-controlled study to proceed to the OLE study until LiBBY OLE is funded. To address the questions stated above, we propose to conduct a 12-week, OLE study to be offered to participants who complete the double-blind, placebo-controlled LiBBY Study.